Coccolithophores 2014 - workshop volume

5

Searching for cells: the potential of fossil coccospheres incoccolithophore researchPaul R. Bown

Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK; p.bown@ucl.ac.uk

Samantha J. Gibbs, Rosie Sheward, Sarah O’dea and david Higgins

Ocean and Earth Science, National Oceanography Centre, Southampton, University of Southampton, Southampton, SO14 3ZH, UK.

Abstract: The majority of fossil coccolithophore studies are based on disaggregated coccoliths but preserved complete

coccospheres provide documentation of true cellular traits (cell size, numbers of coccoliths per cell and calcite quotas) andrepresent a relatively untapped archive of palaeobiological information. Coccospheres are more frequently present when coccolith preservation is good or exceptional. Their preservation is dependent on a variety of taphonomic factors that combine
to minimize the destructive effects of grazing and sinking, seafloor bioturbation and, finally, carbonate diagenesis. Clay-richhemipelagic sediments that have not been deeply buried are particularly productive. Herein, we highlight the occurrences andpotential of these coccosphere fossils and illustrate the range of morphologies we have so far encountered, predominantly fromthe Paleogene interval. Our observations show that coccosphere morphology is generally a conservative, long-lived character,with fossil representatives of living taxa (e.g., Braarudosphaera, Coccolithus, Helicosphaera, Reticulofenestra), all showing
very similar coccosphere style back through their evolutionary history. In addition, we have also observed a variety of sphereshapes (ovoid, ellipsoidal, cylindrical) and significant coccolith polymorphism and varimorphism across a number of different families and in taxa for which fossil coccospheres have not previously been known. Fossil Acanthoica and Calciosolenia
spheres, for example, indicate that polymorphism is a long-lived characteristic of the Syracosphaerales group. Lastly, by
combining morphometric data from both fossil and living populations we show that coccosphere geometries (coccosphere size,
number of coccoliths per coccosphere and coccolith size) show systematic trends (e.g., larger cells have larger coccoliths) but
there is significant divergence from this trend that reflects intrinsic, taxon-specific factors (e.g., coccolith shapes and packing)and growth phase of the population. Although our preliminary coccosphere studies have uncovered new, surprising and usefulobservations we are still far from understanding the fundamental controls on cell size, coccosphere geometry and architecture.

Keywords: fossil coccospheres, Paleogene, Mesozoic
1. Introduction

Palaeontologists studying the long fossil record of coccolithophores have predominantly gathered stratigraphic,taxonomic, palaeoecological and palaeobiological information based on the documentation of disaggregatedcoccoliths, because this is the most common state in which
their cellular remains are found in sea floor sediments.
However, complete coccospheres are also preserved in
the fossil record and with increasing numbers of studies
aiming to understand fossil assemblages as representations of communities of reproducing cells, there isa strong incentive to seek out these complete fossils.
Fossil coccospheres enable the documentation of cellular
traits that can be directly compared with living cells,
including cell size, numbers of coccoliths per cell andcellular calcite quotas (e.g., Henderiks & Pagani, 2007;
Henderiks, 2008; Gibbs et al., 2013). These fossils therefore provide an invaluable archive of important palaeobiological information that can inform all aspects of coccolithophore science, including classification (e.g., throughobservation of coccolith morphology across entire coccospheres), palaeo-growth rates or phase, species-specificcalcite quotas and production rates, and biomineralogicalresponses to changes in palaeoenvironmental conditions
including ocean chemistry.
The images we present here come from ongoing fossil
coccosphere studies, but we would like to highlight theoccurrences and potential of these fossils and illustrate
the range of morphologies we have so far encountered,predominantly in the Paleogene interval.

2. Preserving coccospheres
Coccolithophore coccospheres fall into two main groups:
those capable of maintaining structural integrity after
death and those that collapse into constituent parts oncethe cell and organic binding material has been removed.
The former type is limited to cells with placolith-type
coccoliths (Pl. 1, figs 1-5; Pls 3-10), which both overlap
and interlock, forming a mechanically robust structure,and these are not uncommon in fossil material (e.g., Mai
et al., 1997). The second group form spheres from noninterlocking, murolith-type coccoliths that sit side-byside on the cell surface (Pl. 1, figs 6-9; Pl. 8, fig. 10) andsuch spheres have rarely been seen in the fossil record,with observations limited to a small number of rocksurface scanning electron microscope images, such as
Covington (1985), Lambert (1987, Pl. 4, 9, 10) and Bown
(2010, Pl. 5, fig. 11). In very rare cases these coccospheresare complete and retain their shape, but more commonly
they are collapsed: we consider them coccospheres if they
form a discrete group of numerous coccoliths in close
contact. Finally, non-coccolith (nannolith) or atypicalcoccolith forming groups tend not to have interlocking
coccospheres but can still be preserved as fossils, e.g.,Braarudosphaera (Pl. 7, figs 1-6) and Gladiolithus (Pl.
8, fig. 11).
The frequency of placolith coccosphere occurrence ishighly variable in the fossil record and moderate to poorly
preserved assemblages typically include very few or no
specimens. However, it is becoming increasingly apparent
that the abundance of preserved coccospheres is closely

6

Coccolithophores 2014 - workshop volume

linked to the overall quality of nannofossil preservation
more generally, and well known examples of sedimentsthat host exceptionally preserved nannofossils also typically contain frequent coccospheres. The abundance of
coccospheres is usually apparent in both light microscopeand scanning electron microscope preparations.
In our recent work (e.g., Bown et al., 2008; Bown,
2010; Gibbs et al., 2013) we have focused on the best
preserved fossil coccolithophore material, most typicallyfound in clay-rich hemipelagic sediments that have notbeen deeply buried (e.g., Tanzanian Cretaceous-Paleogene Kilwa Group, New Jersey Paleogene Malboro Clay,Californian Paleogene, Gulf Coast Paleogene Yazoo
Clay). In all of these materials we have observed enhanced
levels of coccosphere preservation. This is perhaps not
surprising, but the preservation of coccospheres is theresult of several distinct taphonomic factors. Coccosphere disintegration can occur at any stage from initialcell death to final preparation of the sample, through both
physical and chemical processes. The mostly likely pointsof loss include initial grazing of the cell and through recycling processes within the photic zone, during sinking
and export from the photic zone, during sedimentation
and burial at the seafloor (in particular, if bioturbation isintense) and finally during lithification and diagenesis,
through compaction and dissolution (e.g., Honjo, 1976;
Wise, 1977; Andruleit et al., 2004). Plankton and trap
studies suggest that most coccospheres are lost throughupper water column processes, but that preservation may
be favoured by initial high abundances (e.g., blooms) and
rapid sedimentation. If coccosphere export to the seafloor
is achieved, it is clear that clay-rich but organic-carbonpoor sediment composition is an important factor in both
coccolith and coccosphere preservation, as impermeable clays minimize the destructive effects of carbonate
diagenesis (Dunkley Jones et al., 2009), and higher sedimentation rates may aid this effect. However, relatively
low seafloor oxygen levels may also play a role, as suchconditions reduce the activity of metazoan bioturbatorsthat would otherwise both churn and ingest sediment andincrease the probability of physical coccosphere destruction, especially the non-placolith forms. Our observationsof unprocessed sediment/rock surfaces in SEM show
undisturbed coccolith- and coccosphere-rich lamina andpellets (Pl. 2), suggesting little or no bioturbation has
occurred. Finally, shelf-sea settings with shorter export
paths and efficient fecal pellet production may also reduce
coccosphere destruction rates during export.
3. Coccosphere and palaeobiologicalobservations
Fossil coccosphere observations are the only definitive way in which we can determine cell size and shape(using the coccosphere architecture) and assess morphological variability of coccoliths associated with single
cells. Overall, our observations suggest that coccospheremorphology is generally a conservative, long-lived

character, with fossil representatives of living taxa (e.g.
Acanthoica, Braarudosphaera, Calciosolenia, Coccolithus, Gladiolithus, Helicosphaera, Reticulofenestra),all showing very similar coccosphere style back throughtheir evolutionary history (Pl. 3-8). Architecturally, themajority of fossil coccospheres that we have observed
are spherical, monomorphic, placolith-bearing types,
and include those of the dominant taxa Watznaueria(Jurassic-Cretaceous), Toweius (Paleocene-early Eocene)
and Reticulofenestra (early Eocene and younger) (Pls 1,
2, 5, 6). Across these individual fossil cells the coccoliths are identical or exhibit very similar shape and size.
However, we have also observed different shaped spheres(ovoid, ellipsoidal and cylindrical) and significant coccolith polymorphism (multiple coccolith types) and varimorphism (varying morphology related to position on
the coccosphere) across a number of families (see Younget al., 1997 for coccosphere terminology). Today, polymorphism is largely restricted to coccospheres of specifictaxonomic groups, especially the Syracosphaerales (Syracosphaeraceae, Calciosoleniaceae and Rhabdosphaeraceae) (e.g., Young et al., 2003, 2005). We have observed
fossil examples of the Syracosphaerales exhibiting polymorphism, e.g., subtle varimorphic coccolith size andspine length variations in Paleogene Acanthoica (Pl. 8,
fig. 8; Dunkley Jones et al., 2009, Pl 8, figs 2; Pl 9, figs
10) and both Cretaceous and Paleogene specimens ofCalciosolenia show varimorphism, with subtle variations
in coccolith length and width (Pl. 1, fig. 8). These Acanthoica and Calciosolenia observations are similar to themorphologies seen in modern species (e.g., Malinverno,
2005; Kleijne, 1992) and suggest that polymorphism is along-lived characteristic of the Syracosphaerales group.
In terms of other non-placolith taxa, we also see variations
in coccolith size in Paleogene Neochiastozygus (Zygodiscales, Zygodiscaceae) (Pl. 8, fig. 10; Bown, 2010 Pl. 5,
fig. 11). Remarkably, coccospheres of the extant nannolith bearing species Gladiolithus flabellatus show that thedimorphic sphere morphology has been conserved overat least 58 million years (Pl. 8, fig. 11; Bown et al., 2009;
Bown, 2010, Pl. 12, 1-4). These fossil coccospheres showthat both lepidoliths and tube coccoliths occur, confirming
the same dimorphism as living forms (Young & Poulton,
this volume). This dimorphism relates to a bowl-shaped
morphology in the modern coccospheres and so it isreasonable to assume that the coccosphere geometry was
the same in the fossil forms.
Fossil placolith taxa with polymorphic coccospheres
include the common Mesozoic species Biscutum
constans, which has ovoid coccospheres with varimorphic coccoliths that reduce in size towards each end of the‘sphere’ (Pl 1, fig. 2). Unusual ‘coccocylinder’ morphologies have also been reported within this genus (Pl 1, fig.
1; Covington, 1985). Similarly, the Paleogene Biscutum
braloweri, frequently seen in the Paleocene-Eocene
thermal maximum (PETM) interval, also displays thisovoid morphology with varying coccolith sizes (Pl. 9), andCoccolithophores 2014 - workshop volume

this may be a coccosphere architecture feature of placolithcoccoliths with relatively narrow elliptical shapes. The
small Paleogene placolith Kilwalithus has a large numberof coccoliths per coccosphere and displays striking dimorphism, with a subset of coccoliths possessing blade-like,arched appendages (Pl. 10).
As well as preserving the ‘finished’ cell covering, thepreservation of intact coccospheres also includes snapshots of growing coccoliths. In both LM and SEM observation, specimens containing proto-coccolith rings are
frequently observed, revealing the partially formed coccoliths formed within intracellular vesicles prior to completion of growth and exocytosis onto the cell surface. Suchspecimens were originally reported by Young & Bown
(1991) and used to reconstruct the ontogeny of Mesozoic
Watznaueria, but we have now found proto-coccolith ringsin almost all the Paleogene placolith taxa (e.g., Toweius Pl 11; Coccolithus - Pl.3, fig. 1, Reticulofenestra - Pl. 6,
figs 1, 2, 4, 7).
4. Coccosphere morphometric data
Our coccosphere morphometric data, first collected forearly Paleogene Toweius and Coccolithus, (Gibbs et al.,2013) show systematic relationships between coccosphere size (external diameter, Ø), number of coccoliths
per coccosphere (CN) and coccolith size (length, CL),
which we collectively refer to as cell geometry. Thereis an obvious trend of larger cells having larger coccoliths (previously documented by Henderiks, 2008) (see,for example, the Reticulofenestra and Coccolithus Pls 3
and 6) but we have recently shown that the relationshipis also dependent on the number of coccoliths forming
the coccosphere, as the same CL can be associated withdifferent Ø by having a variable CN (Gibbs et al., 2013;
see Pl. 4). Certain taxa have geometries which diverge
significantly from this norm, most strikingly seen ingroups that have large numbers of smaller coccoliths per
sphere (e.g., Kilwalithus - Pl. 10, C. primus - Pl. 4, fig.
20, small Toweius - Pl 5, fig. 6), where the relative size ofthe cell is particularly large compared with the coccoliths.
There are also taxa whose coccolith shape or morphology
results in distinctive packing structures, most extreme inthe dodecahedra of Braarudosphaera (Pl 7, figs 1-6), butalso cubiform spheres in Umbilicosphaera bramlettei (Pl4, figs 22-23) and Toweius pertusus (Pl 5, figs 9, 12, 13).
To some extent, coccosphere morphology will therefore
be controlled by coccolith shape and also other factors
intrinsic to the taxon (e.g., cell size), but we have also
observed that coccosphere geometry is a function of
growth phase of the population. Using both culture andfield data we have shown that Coccolithus populations
display a trend away from the general coccolith size tosphere size relationship at different phases of cell division, and a greater relationship between number of coccoliths on a cell versus its sphere size. Recently divided
cells/coccospheres are smaller with fewer coccoliths(19-20µm, 8 coccoliths), growing cells prior to division

7

have large cells and enough coccoliths for the daughter
cells (up to 26 microns, 14-16 coccoliths) and stalled,undividing cells show the largest size and (>26 microns)
and greatest number of coccoliths (>16 coccoliths) (Gibbs
et al., 2013, Fig. 2b). These larger, pre-dividing cells canalso be seen in fossil coccospheres (Coccolithus - Pl 3, fig.
9; Reticulofenestra - Pl 6, fig. 13).
These preliminary results from coccosphere researchusing fossil (and living) populations have uncovered new,surprising and useful observations but we are still far
from understanding the fundamental controls on cell size,coccosphere geometry and architecture. We hope that thispaper demonstrates the potential that is present in thesefossil materials and inspires further discoveries in thisnew area of research. Furthermore, we hope it will stimulate the exploration and documentation of the relationships between coccolith size and shape, and coccospheremorphology in extant coccolithophores and encourage
greater collaboration between those working on the fossil
and living groups.
The Plates
The following plates predominantly illustrate the diversityof Paleogene coccospheres we have so far encountered,
but there are also selected examples of Mesozoic taxa. The
sample location abbreviations are as follows: 647 – ODP
Leg 105, Site 647, NW Atlantic Ocean; 1052 – ODP Leg
171B, Site 1052, Blake Nose, NW Atlantic Ocean; BR –Bass River, New Jersey, USA; HB – Hampden Beach, New
Zealand; LIN – Lindi, Tanzania; LO – Lodo Gulch, Californian, USA; MGr – Mossy Grove, Mississippi, USA;
TDP – Tanzania Drilling Project sites, Tanzania; Tarf. –Tarfaya, Morocco; WL – Wilson Lake, New Jersey, USA.
Sample age abbreviations are as follows: L. – Lower, M.
– Middle, U. – Upper, Alb. – Albian, Eo. – Eocene, Mio.
– Miocene, Oligo. – Oligocene, Pal. – Paleocene. The
LM images are taken from standard smear slide preparations (Young and Bown, 1998) and the SEM images aremostly taken from unprocessed sediment surfaces (Bownet al., 2008). Brief taxonomic notes are provided below
where appropriate. Further information on the detailed
morphometrics and coccosphere geometries of Paleogene
Toweius and Coccolithus and modern Coccolithus andEmiliania are given in Gibbs et al. (2013).
Systematic Palaeontology
Taxa mentioned in the text or illustrated in the plates
are listed below in alphabetical order. Remarks, mainly
regarding coccosphere observations, are given whereappropriate. Abundance information is qualitative but isprovided as a guide to which taxa we have found mostfrequently in our best preserved materials. One new
species, Biscutum braloweri (Pl. 9, figs 1-4), is described.
See Perch-Nielsen (1985), Bown (1998) and the Nannotax
website (ina.tmsoc.org/Nannotax3) for full bibliographic
references.

8

Coccolithophores 2014 - workshop volume

New species
Biscutum braloweri Gibbs & Bown sp. nov.
Pl. 9, figs 1-4
Derivation of name: Named after Timothy Bralower (Penn
State University, USA), nannopalaeontologist, stratigrapher and palaeoceanographer. Diagnosis: Medium-sized
elliptical bicyclic placolith with dark outer-shield image
and bright tube-cycle image. The central area varies fromclosed to narrow with diffuse birefringence suggesting thepresence of a grill or net. Coccospheres are ovoid to ellipsoidal. Differentiation: The coccosphere shape and variable central areas are diagnostic features. The coccoliths
with open central areas are similar to Toweius and withclosed central areas are similar to Prinsius martinii and P.
bisulcus. Dimensions: Coccolith length ~ 6.0 µm. Holotype: Pl.9, fig.3. Paratype: Pl.9, fig. 1. Type locality: ODP
174X onshore drillsite at Bass River (New Jersey coastal
plain, USA). Type level: Upper Paleocene, Sample BR85,
depth 358.02 metres below surface (Zone NP9) Upper
Vincetown Formation. Occurrence: Upper Paleocene
to lowermost Eocene. Possible last occurrence recorded
during the PETM CIE (Zone NP10) as Biscutum? sp. LO’
in Gibbs et al. (2006). Also recorded as Biscutum sp. by
Bralower (2002). Coccospheres found at Bass River and
ODP Site 401 (Bay of Biscay, N. Atlantic Ocean), individual liths from New Jersey, Southern Ocean, Shatsky
Rise (N. Pacific Ocean) and Bay of Biscay.
Taxon list
Acanthoica Lohmann, 1903
Acanthoica backmanii Dunkley Jones et al., 2009
Pl. 8, fig. 8
Remarks: Collapsed coccospheres reveal coccoliths withand without spines.

in shape and varimorphic, with coccoliths that become
smaller towards each end.
Biscutum sp. sensu Covington, 1985 Pl. 1, fig. 1
Remarks: Rare, but forms striking cylindricalcoccospheres.
Braarudosphaera Deflandre, 1947
Remarks: Relatively frequent coccospheres. This is asurprising given the fragility of the coccospheres (i.e., they
are non-interlocking) and this may be due to the shallower
water settings in which Braarudosphaera live or, speculatively, because they are resting cysts that sink to the seafloor
after forming in the plankton. Furthermore, the absence ofany proto-coccolith ring observations is suggestive of amode of biomineralization different from the intracellular
growth seen in heterococcoliths, with lith growth outside
the cell wall but within a membrane most likely.
Braarudosphaera bigelowii (Gran & Braarud, 1935)
Deflandre, 1947 Pl. 7, figs 1-4
Remarks: Relatively frequent coccospheres.
Braarudosphaera aff. B. bigelowii(Gran & Braarud, 1935) Deflandre, 1947
Pl. 7, figs 5-6; Pl. 8, fig. 9
Remarks: Many fossil Braarudosphaera specimens are
similar in general form to the living species Braarudosphaera bigelowii but differ in lith size and sometimes inlith thickness, hence the informal designation given here.
Some size variability is seen in modern Braarudosphaera
bigelowii (Hagino et al., 2009), and may reflect at least
three separate species, however, far greater morphological diversity is seen in the fossil record, especially in the
Paleogene.

Birkelundia Perch-Nielsen, 1971
Birkelundia arenosa Perch-Nielsen, 1971 Pl. 4, fig. 16
Remarks: Large placolith, but rarely reported since its
first description. Large, monomorphic, spherical coccospheres.

Calcidiscus Kamptner 1950
Calcidiscus sp. Pl. 8, figs 5-6
Calciosolenia Gran, 1912
Calciosolenia fossilis (Deflandre in Deflandre & Fert,
1954) Bown in Kennedy et al., 2000
Pl. 1, fig. 8
Remarks: Rare collapsed coccospheres seen on Cretaceous and Paleogene rock surfaces. Subtle variation incoccolith length, width and central area width indicatessimilar varimorphism to that seen on modern Calciosolenia coccospheres (e.g., Malinverno, 2005).

Biscutum Black in Black and Barnes, 1959
Remarks: Rare coccospheres, usually on rock surfaces.

Campylosphaera Kamptner, 1963 not figured
Remarks: Frequent as coccospheres.

Biscutum braloweri Gibbs & Bown sp. nov.
Pl. 9, figs 1-4
Remarks: Coccospheres frequently observed in the PETM
interval.

Chiasmolithus Hay et al., 1966
Remarks: Relatively frequent coccospheres.

Biantholithus Bramlette & Martini, 1964
Biantholithus astralis Steinmetz & Stradner, 1984
Pl. 7, figs 7-9
Remarks: Monomorphic spherical coccospheres.

Biscutum constans (Górka, 1957) Black in Black andBarnes, 1959 Pl. 1, fig. 2
Remarks: Name used for a relatively broad range of
coccolith morphologies, there are fewer observations
on coccospheres but these are often ovoid to ellipsoidal

Chiasmolithus bidens (Bramlette & Sullivan, 1961)
Hay & Mohler, 1967 Pl. 4, figs 12-14
Remarks: Relatively frequent coccospheres. Spherical to‘boxy’ spheres with relatively low number of coccoliths.
Chiasmolithus expansus (Bramlette and Sullivan, 1961)
Gartner, 1970 Pl. 4, fig. 15

Coccolithophores 2014 - workshop volume

Chiasmolithus nitidus Perch-Nielsen, 1971
Pl. 4, figs 9-11
Remarks: Relatively frequent coccospheres. Spherical,
monomorphic coccospheres, but wide range in coccolithand coccosphere sizes.
Clausicoccus Prins, 1979 not figured
Remarks: Relatively frequent coccospheres.
Coccolithus Schwartz 1894 Pl. 3
Remarks: Common coccospheres in LM and on rocksurfaces.
Coccolithus eopelagicus (Bramlette & Riedel, 1954)
Bramlette & Sullivan, 1961 Pl. 3, fig. 11
Remarks: Rare. Spherical monomorphic coccospheres.
Coccolithus pelagicus (Wallich, 1877) Schiller, 1930
Pl. 3, fig. 10
Remarks: Common coccospheres in LM and on rocksurfaces. Spherical, monomorphic coccospheres.
Coronocyclus Hay et al., 1966
Coronocyclus nitescens (Kamptner 1963) Bramlette &Wilcoxon 1967 Pl. 8, fig. 7
Remarks: Rare. Spherical, monomorphic coccosphereswith relatively low number of coccoliths per cell.
Craticullithus Bown, 2010
Craticullithus cancellus Bown, 2010 Pl. 8, fig. 1
Remarks: Rare. Spherical, monomorphic coccospheres.
Cruciplacolithus Hay & Mohler in Hay et al. 1967
Remarks: Relatively frequent coccospheres.
Cruciplacolithus filigranus Mai, 2001 Pl. 8, fig. 3
Remarks: Not reported since its original description. Mai(2001) specimens show spherical monomorphic sphereswith 16-20 coccoliths, but the younger specimen shown
here is a larger coccosphere with >30 coccoliths.
Remarks: Rarely seen as coccospheres in LM and on rocksurfaces.
Cruciplacolithus inseadus Perch-Nielsen, 1969
Pl. 8, fig. 2
Remarks: Relatively frequent coccospheres seen in SEM
but not LM. Spherical, monomorphic coccospheres, butvariable morphologies are seen, including differing size
and number of coccoliths on the spheres (e.g., compare Pl.
8, fig. 2 and Bown, 2010, Pl. 10, fig. 3).
Cruciplacolithus latipons Romein, 1979 Pl. 4, fig. 18
Remarks: Spherical, monomorphic coccospheres.
Cruciplacolithus primus Perch-Nielsen, 1977
Pl. 4, figs 19-20; Pl. 8, fig. 4
Remarks: Spherical, monomorphic coccospheres, but variable morphologies are seen, including differing size andnumber of coccoliths on the spheres (e.g., Pl. 4, fig. 21).
Cruciplacolithus tenuis (Stradner, 1961)
Hay and Mohler in Hay et al., 1967 Pl. 4, fig. 17
Cyclagelosphaera Noël, 1965

9Remarks: Relatively frequent coccospheres, which arespherical and monomorphic.
Cyclagelosphaera reinhardtii (Perch-Nielsen, 1968)
Romein, 1977 Pl. 4, figs 3-4
Remarks: Species that is conspicuous in the PETM
interval. Sometimes difficult to reliably distinguish from
Cyclicargolithus luminis coccoliths (Cyclicargolithus
parvus of Shamrock and Watkins 2012).
Cyclicargolithus Bukry, 1971
Cyclicargolithus floridanus (Roth & Hay, in Hay et al.,1967) Bukry, 1971 Pl. 6, fig. 9
Remarks: Spherical, monomorphic coccospheres. Occur
more frequently as spheres than other reticulofenestrids,
perhaps because they have wider shields (relative to totalsize) that more strongly interlock.
Discorhabdus Noël, 1965
Remarks: Relatively frequently seen as coccospheres.
Discorhabdus ignotus (Górka, 1957) Perch-Nielsen,
1968 Pl. 1, fig. 4
Remarks: Relatively frequently seen as spherical to ovoid,
monomorphic coccospheres.
Gladiolithus Jordan and Chamberlain, 1993
Remarks: Collapsed coccospheres are common on Tanzanian Paleogene rock surfaces.
Gladiolithus flabellatus (Halldal & Markali, 1955)
Jordan & Chamberlain, 1993 Pl. 8, fig. 11
Remarks: Collapsed coccospheres are common on Tanzanian Paleogene rock surfaces (and rare in LM) but are
rarely seen elsewhere. The dimorphism and lith number
seen in the collapsed coccospheres is similar to that seen inmodern specimens (e.g., Young & Poulton, this volume),
indicating the long-lived (~60 million years) conservationof this morphology.
Helicosphaera Kamptner, 1954
Helicosphaera carteri (Wallich 1877) Kamptner, 1954
Pl. 4, figs 1-2
Remarks: Rarely seen in fossil material but ovoid sphereswith spirally arranged coccoliths and apical openings is
identical morphology to that seen in living representatives.
The chiral morphology of Helicosphaera is an adaptationthat facilitates neat interlocking of coccoliths on the coccosphere (Young, 1987). This feature has been conserved
through the ~52 million year evolutionary history of thegenus and has arguably been enhanced by stronger development of the wing (Young, pers. comm., 2014).
Kilwalithus Bown, 2010
Kilwalithus cribrum Bown, 2010 Pl. 10, figs 1-9.
Remarks: Coccospheres are frequently seen on Tanzanian Paleogene rock surfaces and LM slides. Very small
coccoliths but relatively large spheres with high numbersof liths. Spherical coccospheres with varimorphic coccoliths, some having large, arched, processes and somewithout.

10

Coccolithophores 2014 - workshop volume

Markalius Bramlette and Martini, 1964
Remarks: Frequently seen as coccospheres, which arespherical and monomorphic, and composed of consistent
numbers of coccoliths.
Markalius apertus Perch-Nielsen, 1979 Pl. 4, figs 7-8
Remarks: Spherical, monomorphic coccospheres.
Markalius inversus (Deflandre in Deflandre and Fert,
1954) Bramlette and Martini, 1964 Pl. 4, figs 5-6
Remarks: Spherical, monomorphic coccospheres withconsistent number of coccoliths (12).
Neochiastozygus Perch-Nielsen, 1971
Neochiastozygus imbriei Haq & Lohmann, 1976
Pl. 8, fig. 10
Remarks: Collapsed coccospheres rarely seen on rocksurfaces and typically show varimorphism
Pontosphaera Lohmann, 1902 Pl. 2, fig. 2
Prediscosphaera Vekshina, 1959
Remarks: Rarely seen as collapsing coccospheres on rocksurfaces, suggesting relatively low preservation potential.
Prediscosphaera aff. P. columnata (Stover, 1966)
Perch-Nielsen, 1984 Pl. 1. Fig. 5
Remarks: Monomorphic collapsed coccosphere.
Reticulofenestra Hay et al., 1966
Remarks: Spherical, monomorphic coccospheres withwide range of size (~3-40µm in diameter). Considering
the abundance of disaggregated coccoliths and the typicalplacolith structure, they are relatively rarely seen, especially the larger forms.
Reticulofenestra bisecta (Hay et al., 1966) Roth, 1970
Pl. 2, fig. 4; Pl. 6, fig. 12
Remarks: Spherical monomorphic coccospheres.
Reticulofenestra dictyoda (Deflandre in Deflandre &Fert, 1954) Stradner in Stradner & Edwards, 1968
Pl. 2, fig. 4; Pl. 6, fig. 1, 2, 4, 5, 6, 8, 10, 11
Remarks: Spherical monomorphic coccospheres.
Reticulofenestra minuta Roth, 1970 Pl. 6, fig. 3
Remarks: Spherical, monomorphic coccospheres.
Reticulofenestra pseudoumbilicus (Gartner, 1967)
Gartner, 1969; Pl. 6, fig. 13
Remarks: Spherical, monomorphic coccospheres.
Reticulofenestra umbilicus (Levin, 1965) Martini & Ritzkowski, 1968 Pl. 2, fig. 1; Pl. 6, fig. 7
Remarks: Very large, spherical, monomorphic coccospheres. Very rarely seen on rock surfaces.
Rhabdophidites Manivit, 1971 emend. Lambert, 1987
Rhabdophidites parallelus (Wind and Cepek, 1979)
Lambert, 1987 Pl. 2, fig. 3
Remarks: Collapsed coccospheres rarely seen on rocksurfaces and suggest monomorphic coccospheres.
Towieus Hay & Mohler, 1967 Pl. 5
Remarks: Common coccospheres.

Toweius eminens (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1971 Pl. 5, fig. 7
Toweius pertusus (Sullivan, 1965) Romein, 1979
Pl. 5, figs 2, 5. 6, 7-15
Remarks: Common coccospheres that a have consistentmorphology comprising cubiform spheres often made up
of around 6-8 coccoliths.
Toweius serotinus Bybell & Self-Trail, 1995 Pl. 5, fig. 18
Toweius sp. Pl. 5, figs 16-17
Tranolithus orionatus (Reinhardt, 1966a) Reinhardt,
1966b Pl. 1, fig. 9
Tranolithus Stover, 1966
Umbilicosphaera Lohmann, 1902
Umbilicosphaera bramlettei (Hay & Towe, 1962)
Bown et al., 2006 Pl. 4, figs 22-25
Remarks: Spherical to cubiform, monomorphic coccospheres with relatively low number of coccoliths per cell(6-8).
Watznaueria Reinhardt, 1964
Remarks: Common coccospheres, which are sphericaland monomorphic.
Watznaueria barnesiae (Black, 1959) Perch-Nielsen,
1968 Pl. 1, fig. 3
Remarks: Common coccospheres, which are sphericaland monomorphic.
Watznaueria fossacincta (Black, 1971a) Bown in Bown
and Cooper, 1989 Pl. 2, fig. 4
Remarks: Common coccospheres, which are sphericaland monomorphic.
Zeugrhabdotus Reinhardt, 1965
Remarks: Common Mesozoic coccoliths relatively
frequently found as collapsed coccosphere on rocksurfaces.
Zeugrhabdotus sp. Pl. 1, fig. 6 and possibly fig. 7.
Remarks: Collapsed spheres show relatively consistentcoccolith size but some suggestion of varimorphism inspine length.
Acknowledgements

The discovery of many of these geological materials that
contain exceptional nannofossil preservation has often resulted
from the pioneering work of Paul Pearson and Bridget Wade,
who have sought out these sections in their search for thebest preserved planktonic foraminifera. They have been very
generous in sharing their sample material and providing fruitfulcollaborations, more generally, and we gratefully acknowledge
their generosity. We also acknowledge the provision of sample
material that has come from Ocean Drilling Program and the
Tanzania Drilling Program, and also for the funding of parts ofthis research by the Royal Society, NERC and the UK Ocean
Acidification Programme. Thanks to Jeremy Young and Jorijntje
Henderiks for their positive and constructive reviews, which
improved the manuscript.

Coccolithophores 2014 - workshop volume

References
Andruleit, H., Rogalla, U. & Stäger, S. 2004. From living
communities to fossil assemblages: origin and fate ofcoccolithophorids in the northern Arabian Sea. Micropaleontology, 50 (supl. 1): 5-21.
Bown, P.R. 2010. Calcareous nannofossils from the Paleocene/Eocene Thermal Maximum interval of southern
Tanzania (TDP Site 14). Journal of Nannoplankton
Research, 36: 11-38.
Bown, P.R. & Young, J.R. 1998. Techniques. In: Bown,
P.R. (Ed.), Calcareous Nannofossil Biostratigraphy.
Kluwer Academic, London: 16–28.
Bown, P.R., Dunkley-Jones, T., Lees, J.A., Randell, R.D.,
Mizzi, J.A., Pearson, P.N., Coxall, H.K., Young, J.R.,
Nicholas, C.J., Karega, A., Singano., J. & Wade, B.S.
2008. A Paleogene Calcareous microfossil KonservatLagerstatte from the Kilwa Group of coastal Tanzania.
GSA Bulletin, 120: 3-12.
Bown, P. R., Dunkley Jones, T., Young, J.A. & Randell,R. 2009. A Palaeogene record of extant lower photic
zone calcareous nannoplankton. Palaeontology, 52:
457-469.
Bralower, T.J. 2002. Evidence of surface water oligotrophy during the Paleocene-Eocene Thermal Maximum:
Nannofossil assemblage data from Ocean Drilling
Program Site 690: Maud Rise, Weddell Sea. Paleoceanography, 17: 1–13.
Covington, J.M. 1985. New morphologic information on
Cretaceous nannofossils from the Niobrara Formation(Upper Cretaceous) of Kansas. Geology, 13: 683-686.
Dunkley Jones, T., Bown, P.R. & Pearson, P.N. 2009.
Exceptionally well preserved upper Eocene to lower
Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology, 7: 359-411.
Gibbs, S.J., Bown, P.R., Sessa, J.A., Bralower, T.J. & Wilson, P.A. 2006. Nannoplankton origination and extinction across the Paleocene-Eocene Thermal Maximum.
Science, 314: 1770-1773.
Gibbs, S.J., Poulton, A.J., Bown, P.R., Daniels, C., Hopkins, J., Young, J.R., O’Dea, S.A., and Newsam, C.
2013. A cellular perspective on plankton sensitivity
to past global climate change. Nature Geoscience, 6:218-222.
Hagino, K., Takano, Y. & Horiguchi, T. 2009. Pseudocryptic speciation in Braarudosphaera bigelowii(Gran and Braarud) Deflandre. Marine Micropaleontology, 72: 210-221.
Henderiks, J. 2008. Coccolithophore size rules - Reconstructing ancient cell geometry and cellular calcite
quota from fossil coccoliths. Marine Micropaleontology, 67: 143-154.
Henderiks, J. & Pagani, M. 2007. Refining ancient carbon
dioxide estimates: Significance of
coccolithophore
cell
size
for
alkenone-based
pCO2 records. Paleoceanography, 22: PA3202,
doi:10.1029/2006PA001399.

11

Honjo, S. 1976. Coccoliths: production, transportationand sedimentation. Marine Micropaleontology, 1:
65-79.
Kleijne, A. 1992. Extant Rhabdosphaeraceae (coccolithophorids, class Prymnesiophyceae) from the Indian
Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Scripta Geologica, 100: 1-63.
Lambert, B. 1987. Nannofossiles calcaires de l’Albien
supérieur et du Vraconnien du Cameroun méridional.
Cahiers de micropaleontology, 2: 33-60.
Mai, H., von Salis Perch-Nielsen, K., Willems, H. &Romein, A.J.T. 1997. Fossil coccospheres from theK/T boundary section from Geulhemmerberg, The
Netherlands. Micropaleontology, 43: 281-302.
Mai, H. 2001. New Coccolithophorid Taxa from Geulhemmerberg Airshaft, Lower Paleocene, the Netherlands. Micropaleontology, 47: 144-154.
Malinverno, E. 2004. Morphological variability within
the genus Calciosolenia (coccolithophorids) from theeastern Mediterranean Sea. Micropaleontology, 50(supl. 1): 81-91.
Perch-Nielsen, K., 1985. Cenozoic calcareous nannofossils. In: H.M. Bolli, J.B. Saunders & K. Perch-Nielsen(Eds), Plankton Stratigraphy. Cambridge University
Press, Cambridge: 427–554.
Shamrock, J.L. & Watkins, D.K. 2012. Eocene calcareous
nannofossil biostratigraphy and community structurefrom Exmouth Plateau, Eastern Indian Ocean (ODPSite 762). Stratigraphy, 9: 1-54.
Wise, S.W. 1977. Chalk formation: early diagenesis. In
N.R. Anderson & A. Malahoff (Eds), The fate of fossil
fuel CO2 in the oceans. New York, Plenum Publishing
Corp.: 717-739.
Young, J.R. 1987. Possible functional interpretationsof coccolith morphology. Abhandlungen der Geologischen Bundesanstalt, 39: 305-313.
Young, J.R., Bergen, J.A., Bown, P.R., Burnett, J.A., Fiorentino, A., Jordan, R.W., Kleijne, A., van Niel, B.E.,
Romein, A.J.T. & Salis, K.v. 1997. Guidelines for coccolith and calcareous nannofossil terminology. Palaeontology, 40: 875-912.
Young, J.R. & Bown, P.R. 1991. An ontogenetic sequenceof coccoliths from the Late Jurassic Kimmeridge Clayof England. Palaeontology, 34: 843-850.
Young, J.R., Geisen, M., Cros, L., Kleijne, A., Sprengel,
C., Probert, I. & Ostergaard, J. 2003. A guide to extant
coccolithophore taxonomy. Journal of Nannoplankton
Research Special Issue 1.
Young, J.R., Geisen, M., & Probert, I. 2005, A review
of selected aspects of coccolithophore biology with
implications for paleodiversity estimates. Micropaleontology, 51: 267-288.
Young, J.R., Bown, P.R. & Lees, J.A. 2014. Nannotax3:
http://ina.tmsoc.org/Nannotax3.
Young, J.R. & Poulton, A.J. this volume. Gladiolithus
adeyi a new deep photic coccolithophore species.
Journal of Nannoplankton Research.

12

Coccolithophores 2014 - workshop volume

Plate 1
Examples of placolith coccospheres and murolith coccospheresCoccolithophores 2014 - workshop volume

Plate 2
Examples of rock surfaces with coccospheres

13

14

Coccolithophores 2014 - workshop volume

Plate 3
Coccolithus pelagicus

Coccolithophores 2014 - workshop volume

Plate 4
Helicosphaeraceae, Coccolithaceae and Calcidiscaceae

15

16

Coccolithophores 2014 - workshop volume

Plate 5
Prinsiaceae

Coccolithophores 2014 - workshop volume

Plate 6
Reticulofenestra

17

18

Coccolithophores 2014 - workshop volume

Plate 7
Braarudosphaera and BiantholithusCoccolithophores 2014 - workshop volume

Plate 8
Miscellaneous

19

20

Coccolithophores 2014 - workshop volume

Plate 9
Biscutum braloweriCoccolithophores 2014 - workshop volume

Plate 10
Kilwalithus cribrum

Plate 11
Toweius protococcolith rings

21

PDF vs. Published copy
In the published version of this paper the images on plate 9 were mislabelled, this has been correctedin this PDF version. In addition plate 2 has been rotated. No other changes have been made.
JRY Nov. 2014